Nucleophosmin is required for chromosome congression, proper mitotic spindle formation, and kinetochore-microtubule attachment in HeLa cells.
Nucleophosmin (NPM) is an abundantly expressed multifunctional nucleolar phosphoprotein. Here we show that depletion of NPM by RNA interference causes defects in cell division, followed by an arrest of DNA synthesis due to activation of a p53-dependent checkpoint response in HeLa cells. Depletion of NPM leads to mitotic arrest due to spindle checkpoint activation. The mitotic cells arrested by NPM depletion have defects in chromosome congression, proper mitotic spindle and centrosome formation, as well as defects in kinetochore-microtubule attachments. Loss of NPM thus causes severe mitotic defects and delayed mitotic progression. These findings indicate that NPM is essential for mitotic progression and cell proliferation.
Amin
Mohammed Abdullahel
MA
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan.
Matsunaga
Sachihiro
S
Uchiyama
Susumu
S
Fukui
Kiichi
K
D020090:Chromosome Segregation / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D000090243:Nucleophosmin; D034622:RNA Interference; D008941:Spindle Apparatus / Q000235:genetics* / Q000378:metabolism
C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D000090243:Nucleophosmin